Power-translating system.



No. 741,471. PATENTED OOT. 13,1903.

' A. c. EASTWOOD.-

POWER TRANSLATING SYSTEM.

APPLICATION FILED AP-R. a. 1903,

' fwamiom- Matias/h0g out my invention.

Patented October 13, 1903.

PATENT OEEIcE.

ART HUB C. EASTWOOD, OF CLEVELAND, OIIIO.

POWER-TRANSLATING SYSTEM.

SPECIFICATION forming part of Letters Patent N 0. 741,471, dated October13, 1903.

Application filed April 8, 1908. Serial No. 160,969. (No model.)

To all whom it 77 1/6711] concern:

Be it known that I, ARTHUR O. EAsrwooD, a citizen of the United States,and a resident of Cleveland, Ohio, have invented certain Improvements inPower-Translating Systems, of which the following is a specification.

My invention consists in certain improve ments in methods forcontrolling the operation of mechanism or devices actuated from a driveror prime mover which itself is operated continuously at a constantspeed.

The object of the invention is to provide a method whereby power may beefficiently transmitted from a driving element or source of poweroperating at a substantially constant speed to a power-receiving devicethrough a device intermediate of said two members by which the speed ofthe driven member may be varied within any desired limits. This object Iattain as hereinafter set forth, reference being had to the accompanyingdrawings, in which Figure l is a plan View showing in diagram onearrangement of apparatus for carrying Figs. 2 to 5, inclusive, arediagrammatic views illustrating some of the possible connections of theparts of the electric device interposed between the driving and thedriven members of the system to vary the speed of said driven member,and Fig. 6 is a diagrammatic view showing another arrangement ofconnections for controlling the action of the electric machine andconsequently the speed of the load driven.

In the above drawings, A represents any desired form ofdriver, such as asynchronous motor or any other desired form of motor designed to operateat a constant speed. It will be understood that for said -n1otor may besubstituted an internal-combustion or other engine, the object beingthat the driver operating at a constant speed shall turn one element, asB, of an electric machine. The said electrical machine is so made thatboth of its elements are free to rotate, and in the present instance Ihave shown the field-frame operatively connected, by means of a belt a,to the motor A.

The armature O of the electric machine is in the present instancesupported upon a one hundred and fifty conductors.

shaft D, having a wheel or gear (Z, through which power is transmittedto.any form of power-receiving apparatus.

The armature O is constructed with two commutators c and c and twoindependent series of windings c and 0, each connected to one of saidcommutators, and I preferably so design said armatures that they havedifferent numbers of turns-as, for example, the armature-Winding c hasone hundred active conductors, while the winding 0 has The fieldwindingcarried on the frame B is preferably connected in shunt to the terminalsof the brushes (not shown) belonging to the commutatonof one of the setsof armature-conductors, and I preferably insert a variable resistance 0in circuit with said field-coil, so as to be able to alter the strengthof the field of the electric machine at will, the current for saidfield-windings being supplied through rings 0 of the well-knownconstruction.

It will be understood that the field-Wind'- ing is not necessarilysupplied with current from one of the armature-windings c or c, as inpractice it could be fed from astorage battery or from the eXciter usedin connection with the alternating-current motor. If desired, oneportion of the field may be energized by current from a source externalto the machine, while other portions may be connected, respectively, inseries with the terminals of the two armature-windings, as shown in Fig.(5.

By means of any suitable form of controller connected in circuit withthe two sets of armature-terminals I am enabled to change at will thenumber of effective turns on the armature considered as a whole. Forexample, if, as in Fig. 2, I connect the winding 0 so that itsconductors act in opposition to those of the winding 0 there will befifty effective turns in operation, while, as in Fig. 3, if theterminals of the windingc are short-circuited, while those of thewinding 0 are open-circuited, there will be one hundred effective turnsin action. Similarly if the terminals of the wind ing 0 be connected toeach other and those of. the winding 0 be left open there will be onehundred and fifty turns in action on the armature, and if both sets ofthe terminals be connected so that they act in series with each otherthere Willbe two hundred and fifty conductors in action.

In operation the prime mover A is permitted to run continuously, turningthe element 13 of the electric machine at a constant speed, and grantingthat there is a load connected to the shaft D through the wheel d thenelectrically connecting the two sets of terminals of the windings o andc, as shown in Fig. 2, will result in fifty turns or conductors becomingelfective on the armature, which will be then started and pulled aroundafter the rotating element B, though at a speed less than the speed ofrotation of said element, by an amount known as the slip. This slip, andhence the speed of the armature C, may be varied by differentcombinations of the two windings c and c, as set forth above andasindicated in Figs. 2 to 5, or, if desired, there may be inserted inthe field-circuit varying amounts of the resistance 0, by which thestrength of the field can be varied, thus further altering the amount ofslip between the elements 0 and B. It will be understood that these twomethods of varying the slip, and consequently the relative speed of thetwo elements of the electric machine, may be and preferably are to beused together, the comparatively large changes of speed being secured bythe change in the number of effective armatureconductors and the smallerchanges being secured by varying the field strength, though thesecharacteristics may be altered or varied separately without departingfrom my invention.

Since the total current for the field-winding will not under ordinaryworking conditions with efficient design exceed two per cent. of thecapacity of the machine, it will be seen that the insertion of theresistance a will not materially affect the efficiency of the system.

By the above-described device I am enabled to operate the driving-motorat a constant speed and by means of the electric con-' necting devicecomprised by the two elements B and C to vary the speed of the drivenmember of the system within any practicable limits, which may bedetermined by and depend upon the electrical characteristics of thedevice.

I claim as my invention 1. The method of transmitting power from adriving to a driven member, the same consisting in interposing betweenthe two members an electric machine having its elements movablyconnected respectively to said members, operating the driving member ata substantially constant speed and varying the speed of the drivenmember by altering the electrical characteristics of the two elements ofthe electrical machine, substantially as described.

2. The method of transmitting power from a driving to a driven member,the same consisting in operating one element of an eloctric machine fromsaid driving member at a constant speed, operating the driven memberfrom a second element of the electric machine, supplying current from anexternal source to one of the elements of said electric machine andchanging the relative velocities of the two members by varying thenumber of effective turns on the other element of the electric machinesubstantially as described.

3. The method of transmitting power from a driving to a driven member,the same consisting in operating one element of an electric machine fromsaid driving member at a constant speed, operating the driven memberfrom the second element of the electric machine, exciting the field ofthe electric machine and changing the relative velocities of the twomembers by varying the number of effective turns on the armature of saidelectric machine, substantially as described.

4:. The method of transmitting power from a driving to a driven member,the same consisting in interposing between them an electric machinehaving its elements movably connected respectively to said two members,operating the driving member at a constant speed and varying the speedof the driven member by changing the number of effective conductors onthe armature and altering the strength of the field of said electricmachine, substantially as described.

5. The method of transmitting power from a driving to a driven member,the same consisting in starting and operating at a constant speed onemember of an electric machine rotatably connected to said driving memberand independent of the load to be driven, starting the said load byclosing the circuit of the electric machine interposed between it andthe driving member independently of the external sources of current, andvarying the speed of the load by changing the electric characteristicsof said interposed machine, substantially as described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

ARTHUR O. EASTWOOD.

Witnesses:

LA RoY RAUDENBUSH, Jos. H; KLEIN.

